Liquid crystal display devices can have a smaller thickness and lower power consumption, and therefore, are widely used as a display for a mobile information apparatus, such as a television set, an OA apparatus (e.g., a personal computer, etc.), a mobile telephone, a personal digital assistant (PDA), etc.
A liquid crystal display device includes a liquid crystal display panel, and a backlight unit attached to the back surface of the liquid crystal display panel. The liquid crystal display panel includes an array substrate including switching elements (e.g., thin film transistors, etc.), and a counter substrate facing the array substrate, which are bonded together by a sealing member. A liquid crystal material is enclosed in a space between the two substrates. The counter substrate is slightly larger than the array substrate, and therefore, a portion of the array substrate is exposed. On such an exposed region (terminal region), a drive circuit is mounted.
The liquid crystal display panel has a display region in which an image is displayed and a non-display region which surrounds the display region.
An alignment film is formed in a surface contacting the liquid crystal layer of the array substrate, covering at least the display region. Similarly, an alignment film is formed in a surface contacting the liquid crystal layer of the counter substrate, covering at least the display region.
The alignment film may be formed by forming a resin film made of polyimide, etc., by flexographic printing, inkjet printing, etc., and performing a rubbing treatment on a surface of the resin film. Inkjet printing is preferably used for the formation of the resin film for the following reasons: the resin film can be applied directly to the substrate; contamination can be reduced due to the non-contact process; the amount of solution consumed can be reduced; the time required can be reduced; etc.
Incidentally, when inkjet printing is used to form the alignment film, a resin material having a lower viscosity than that used in flexographic printing is used as a material for the alignment film, and therefore, the alignment film material is likely to leak and spread into a region around a region (display region) in which the alignment film should be printed. Therefore, if the non-display region around the display region is so small that a large space cannot be ensured between the display region and the sealing member region, the alignment film may flow into the sealing member region. In this case, the adhesiveness between the sealing member and the alignment film is insufficient, and therefore, the gap between the two substrates cannot be completely sealed, so that the liquid crystal material of the liquid crystal layer may leak.
In order to solve the above problem, PATENT DOCUMENT 1 describes a liquid crystal display device including a groove portion which is provided in a generally annular region which is located outside the display region and inside the region in which the sealing member, and extends along an outer perimeter of the display region. With this configuration, even if the liquid resin material applied by inkjet printing spreads to the outside of the display region, the groove portion can reduce or prevent the resin material from further spreading, whereby the spread outside the display region of the alignment film can be reduced or prevented. PATENT DOCUMENT 1 also describes a configuration in which a conductive film, such as an ITO film, etc., is formed on a surface of the groove portion. The liquid resin material which is the alignment film material has a low wettability to the ITO film. Therefore, this configuration allows the groove portion to reduce or prevent the liquid resin material from wetting and spreading.